Page 1 of 8 1234 ... LastLast
Results 1 to 10 of 79
  1. #1
    Veteran Member deerefan's Avatar
    Join Date
    Aug 2005
    Posts
    1,667
    Location
    louisiana
    Tractor
    1952 8N, 2005 JD 5103

    Default GM 5.3 gas mileage

    I bought a 2011 Z71 4x4 ext cab in December. It has the tow package and 3.42 gears with the 6 spd auto. I have about 5500 miles on it and am averaging 15.8 mpg hand calculated. I find this rather disappointing considering my 97 F150 4x4 ext cab with the 4.6, 4 spd auto and 3.55 gears get 15 flat. Here we are 14 years later and light years ahead in technology and the mileage is basically the same. I can't call GM a liar as it states 15-21 mpg on the sticker and I am getting 15.8 (the computer mpg says 16.3 avg). For comparison, my father has a 2010 avalanche, 2wd 3.42 gears and he is seeing 18-19 mpg. I drive normally, not lead footed. Another thing I noticed is at 62 mph, I am turning the same rpm as my ford. Weird considering my trans has 2 more gears than the ford. Anyone have the same truck? What mpg are you getting?

  2. #2
    Super Member houstonscott's Avatar
    Join Date
    Dec 2010
    Posts
    5,467
    Location
    Oglesby, Texas
    Tractor
    Kubota L3800, Kubota GR2120, Kubota RTV1100, Kubota 5100sc

    Default Re: GM 5.3 gas mileage

    I have a 09 Z71 suburban 4x4 with same engine transmission and gearing. I average about 17.5 on the computer over 40K on the truck.

    HS

  3. #3
    Elite Member jonyyuma's Avatar
    Join Date
    Sep 2010
    Posts
    2,972
    Location
    35 miles North of Memphis,TN
    Tractor
    kubota L3000dt, ford 8n1952

    Default Re: GM 5.3 gas mileage

    Reading your facts is astounding.. My 1973 Chevy 307/ {350 later} had 3 on tree and 3.40 gear. It pulled 15mpg and 14 mpg respectively. Now does your 6 speed include overdrive? Seems like something is missing here, other than does your 4x4 , become a 2wd, or is it maintained ? Btw my Son drives a 97 ford 4x4 same as yours and it does the same mpg with a whole lot of miles on it..
    Okay, Legal disclaimer: Old but not senile, definitely do not have the answer to everything!

  4. #4
    Silver Member
    Join Date
    Sep 2007
    Posts
    152
    Location
    Western MA
    Tractor
    JD 110 TLB

    Default Re: GM 5.3 gas mileage

    That seems off. I had the exact same truck as you except it was a 2005 which only had the 4 spd auto. In the summer I always averaged 17.5 mpg mixed driving, winter dropped usually 2 mpg with the different fuel. I would think you should average 18 to 19 mpg. Highway the truck was always 19-20 mpg up to about 75 mpg, and didn't drop too much doing 85 or so. This was all hand calculated.
    2004 JD 110 TLB, Kubota TG 1860G, 16' 14k dump trailer, and 2008 F350 SRW CC V10, and many useful accessories.

  5. #5
    Super Star Member LD1's Avatar
    Join Date
    Apr 2008
    Posts
    14,784
    Location
    Central Ohio
    Tractor
    Kubota MX5100

    Default Re: GM 5.3 gas mileage

    Quote Originally Posted by deerefan View Post
    I bought a 2011 Z71 4x4 ext cab in December. It has the tow package and 3.42 gears with the 6 spd auto. I have about 5500 miles on it and am averaging 15.8 mpg hand calculated. I find this rather disappointing considering my 97 F150 4x4 ext cab with the 4.6, 4 spd auto and 3.55 gears get 15 flat. Here we are 14 years later and light years ahead in technology and the mileage is basically the same. I can't call GM a liar as it states 15-21 mpg on the sticker and I am getting 15.8 (the computer mpg says 16.3 avg). For comparison, my father has a 2010 avalanche, 2wd 3.42 gears and he is seeing 18-19 mpg. I drive normally, not lead footed. Another thing I noticed is at 62 mph, I am turning the same rpm as my ford. Weird considering my trans has 2 more gears than the ford. Anyone have the same truck? What mpg are you getting?
    I had an 03 with the 5.3. Not sure on the tranny, 4speed? maybe 5?? and I could get around 16MPG like you. Loaded with a trailer and tractor @ ~6500lbs, I would only get 9-10MPG.

    But you are right, I dont think we are getting anywhere with the mileage on these trucks. A lot of it is emissions BS, but I think we could still do better and we are not.

    Dad had a 1985 chevy K20. 3/4 ton, 4wd, 3-speed w/ granny, 350 carbureted. And he could get 15MPG. He was utterly disappointed when he traded it (many years ago) for a 1998 dodge w/360 and couldnt do any better. And then again, when he got a 2005 dodge w/hemi and still...14-15MPG. It seems in almost 30 years, there has been NO improvement to MPG. Even with double the gears in the tranny
    ".........there is only one way to find out."
    "Ok, hold my beer and watch this.........."


    Ford 5500 Backhoe
    Kubota MX5100HST w/LA844
    2005 Dodge 3500 4x4 Diesel
    8N Rebuilt and restored
    Bushhog 306
    3 Homemade wood hauling trailers
    Dolmar 6400 84cc ported
    Sachs-Dolmar 120SI Ported
    (4) Sachs-Dolmar 116SI Ported
    Dolmar PS540
    Sachs-Dolmar 115i
    Sachs-Dolmar 117
    Sachs-Dolmar 112

  6. #6
    Elite Member jonyyuma's Avatar
    Join Date
    Sep 2010
    Posts
    2,972
    Location
    35 miles North of Memphis,TN
    Tractor
    kubota L3000dt, ford 8n1952

    Default Re: GM 5.3 gas mileage

    Ld1, Yes there has been a bunch of different engines, some of the guys here has gone to nearly straight exhaust and not cats, still not getting the advertized mileage.. I had headers and turbo exhaust on my old 73 and never even raised it 1 mpg. But I do not see how these guys feed those Hemis...?I read comsumer reports and they raised 9 mpg in city?
    Okay, Legal disclaimer: Old but not senile, definitely do not have the answer to everything!

  7. #7
    Veteran Member
    Join Date
    Jun 2004
    Posts
    2,035
    Location
    Lexington, NC

    Default Re: GM 5.3 gas mileage

    Here 2007 NBS 5.3 w/ 3.73 & 4 spd. auto gets approx. 15-16mpg average and I have gotten as high as 20 highway alone. In 121,000 miles the average on the computer is 16.9mpg. Almost exactly the same as all models I've had w/ 5.3 eng. regardless of rear end ratio.
    "Look at Him at Gethsemane, sweating as it were great drops of blood; look at Him on the cross, crucified between two thieves; hear that piercing cry, "Father, Father, forgive them, they know not what they do." And as you look into that face, as you look into those wounds on His feet or His hands, will you say He has not the power to save you? Will you say He has not the power so redeem you?" D.L. Moody

  8. #8
    Elite Member
    Join Date
    Mar 2010
    Posts
    2,511
    Location
    Ontario
    Tractor
    CT235

    Default Re: GM 5.3 gas mileage

    It takes X amount of horsepower to push a 4x4 through the air at any given speed. That required HP is directly proportional to the amount of fuel you use.

    Doesn't matter what gearing, what engine, whatever.....

    Speed is the enemy for fuel economy with these trucks. Even my Explorer will touch 30mpg if I stay under 50mph, with no head wind, warm air, etc....

    Your consumption will go up exponentially with your speed. It is not linear.
    Tim.

  9. #9
    Silver Member dixstir's Avatar
    Join Date
    Dec 2009
    Posts
    218
    Location
    fairmont mn
    Tractor
    2305 jd cub farmall home made tractor

    Default Re: GM 5.3 gas mileage

    maybe to new of a truck mine gets 20-22 hwy (1957 chevy 3 speed overdrive and a 342 rear gear) I think I will keep it but my 2002 gmc 4.8 get around 20 not much dif in all those years.

  10. #10
    Super Member timswi's Avatar
    Join Date
    Nov 2008
    Posts
    5,427
    Location
    Beaver County Pa
    Tractor
    Kubota BX23 TLB, Kubota RTV1100, Kubota Z724 & Polaris Sportsman 570 Touring

    Default Re: GM 5.3 gas mileage

    I average around 16mpg with mixed driving..2011 GMC 6.2 6sp 3:42 4x4. I run it pretty hard though, 70+ mph going to work.

    On the highway, taking it easy, I can get 19-20 depending.
    BX23TLB with 54" MMM
    RTV1100 with 72" Power Angle Plow
    Z724 ZTR
    Polaris Sportsman 570 Touring

Page 1 of 8 1234 ... LastLast

Similar Threads

  1. F250 5.4 gas mileage
    By Kahuna in forum Trailers & Transportation
    Replies: 42
    Last Post: 08-20-2012, 10:12 AM
  2. So, You think you own your land...
    By JazzDad in forum Rural Living
    Replies: 108
    Last Post: 03-07-2009, 10:20 PM
  3. Diesel theft at the gas station
    By Keith01 in forum Oil, Fuel & Lubricants
    Replies: 16
    Last Post: 06-04-2008, 11:51 PM
  4. locking fuel caps for tractors?
    By accordionman in forum Attachments
    Replies: 13
    Last Post: 06-02-2008, 05:10 PM
  5. Powerstroke 6.0 gas mileage
    By GreatWhitehunter in forum Trailers & Transportation
    Replies: 19
    Last Post: 02-11-2007, 06:20 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2016 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.